Agents of S.H.I.E.L.D. star Clark Gregg "accidentally" posted some behind-the-scenes images from the show's upcoming final season on his Instagram page Saturday.

The pics show Gregg and fellow cast member Chloe Bennet in old-fashioned clothing, apparently from the 1930s, which is when the seventh season is supposed to take place. Previous images that were captured on set showed the characters donning similar outfits.

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"Oh no. Accidentally posted a BTS shot from #agentsofshield s.7," Gregg captioned his post. "I better delete this. Soon."

In a follow-up post, which showed Gregg firing off a Tommy gun, the actor said, "Crap! I did it again! This stuff is classified. So sorry." He concluded his photo flurry with Bennet's picture and a caption that read, "Wow. It must be some kind of glitch."

The seventh season of Agents is expected to pick up where Coulson, Daisy, Mack and Deke left off -- and that's in the year 1931. Last year's trailer showed a trio of chromicon hunters taking out some corrupt cops in New York City.

Marvel's Agents of S.H.I.E.L.D. will return in the summer for its final season on ABC. The series stars Ming-Na Wen, Chloe Bennet, Henry Simmons, Iain De Caestecker, Natalia Cordova-Buckley, Elizabeth Henstridge and Clark Gregg.

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